Data conversion circuitry that converts analog signals into digital signals for processing by a digital signal processor is well known to those skilled in the art. There are a variety of circuits and techniques that may be used for analog-to-digital (A/D) conversion. In addition it is well-known to use A/D circuits for housekeeping chores in devices such as receiving signals from various sensors and converting those signals into digital signals for interpretation and utilization by a controller. For example, in portable electronic devices such as cellular telephones, A/D circuits could be used for housekeeping chores such as monitoring the battery voltage and/or the battery current, monitoring the charging voltage, monitoring die temperature or monitoring touchscreen pressure points. Cyclic A/D circuits, such as redundant signed digit (RSD) cyclic A/D circuits, are suitable for such housekeeping chores.
As can be easily understood, there could be a large number of housekeeping cyclic A/D circuits. Each cyclic A/D circuit consumes power and takes up space. Portable electronic devices are becoming smaller and smaller and have limited power, therefore size and power have become critical design parameters. Thus, what is needed is an improved cyclic A/D circuit with reduced size and reduced power consumption.